In general preoperative patient positioning, anesthesia management, echocardiographic evaluation with repair planning, the operative set-up, and perfusion techniques are the same for all of our robotic and nonrobotic MIMVS. For both approaches the patient should be positioned with the right chest elevated by 30 degrees on a commercial lift or a cloth roll. The right arm should be distracted laterally and supported safely inferior to the posterior axillary line. The right axillary area should be exposed to insert the transthoracic aortic cross-clamp. Standard skin preparation and draping should provide wide exposure to the right chest, sternum, and both groins.

In most operations our anesthesiologists prepare patients as shown in Figure 18.1. These preparations include placing the following:

Today, most minimally invasive and robotic mitral valve operations are performed through a right-side fourth intercostal mini-thoracotomy. The choices for visualization include a direct view through the incision, 2D endoscopic, or 3D robotic. Recently 3-D non-robotic endoscopes have been developed. The size of the working incision usually relates to both the visualization and operative method chosen by the surgeon. For both direct vision and 2D endoscopic MIMVS, a 4- to 5-cm mini-thoracotomy is made in the fourth intercostal space at the anterior axillary line. Smaller port-access incisions (2 to 3 cm) are made in the same area for robotic operations. We place a flexible Alexis soft tissue wound protector (Applied Medical, Inc., Rancho Santa Margarita, Calif.) in preference to using a rib-spreading retractor. We have found that this minimizes postoperative pain and provides good working-incision exposure for either direct vision, endoscopic, or robotic MIMVS.

All perfusion cannulas are placed under echocardiographic guidance using the Seldinger guidewire technique. The right femoral artery is cannulated with either a 17-Fr or 19-Fr Bio-Medicus cannula through a 2-cm oblique groin incision. For inferior vena caval drainage, either a 22-Fr (single stage) or a 23-Fr/25-Fr (dual stage) RAP femoral venous cannula (Estech, San Ramon, CA) is passed into the right atrium (Fig. 18.2). Vacuum-assisted venous drainage is used in all of these operations. Intrathoracic carbon dioxide is insufflated throughout each operation to minimize the amount of intracardiac air entrapment. To monitor adequate limb perfusion, during CPB, oxygen saturation levels are monitored continuously in each leg using the Invos system (Somanetics Inc., Troy, MI). If a significant arterial saturation decrease occurs in the cannulated leg during CPB, we place a distal superficial femoral artery 5-Fr catheter and connect it to the arterial perfusion circuit. To date, we have had no problems with residual leg ischemia.

For aortic occlusion, we use a transthoracic cross-clamp (Scanlan International, St. Paul, MN) as it has been proven to be safe, reliable, economic, and simple to apply (Fig. 18.3). The posterior clamp tine should be passed through the transverse sinus under either direct or videoscopic vision. The anterior tine is positioned across the aorta until it reaches the main pulmonary artery (Fig. 18.4). Care must be taken not to injure the right pulmonary artery, left atrial appendage, left main coronary artery, or aorta.

Some surgeons prefer to use endoaortic balloon occlusion. This technique has a steeper learning curve than using the clamp. The balloon position must be precise and remain stable in the ascending aorta. There is a potential for either innominate artery occlusion or intraventricular displacement. Therefore, TEE monitoring of balloon position throughout the operation is mandatory. Also, balloon catheter introduction through the femoral arterial cannula can limit perfusion flow. In this circumstance the endoballoon catheter should be inserted through the other femoral artery. Despite these concerns, this method can provide effective aortic occlusion, a route for delivering antegrade cardioplegia, and an air vent without needing a separate aortic root cannula.

As mentioned, we have always used the transthoracic aortic clamp method for both minimally invasive and robot-assisted mitral valve surgery. A pledgeted diamond-shaped 4-0 PTFE purse-string suture is placed in the ascending aorta and proximal to the fatty fold of Rindfleisch. For antegrade cardioplegia administration, a long cardioplegia-vent catheter (Medtronic, Inc., St Paul, MN) is inserted through the purse strung suture, secured and then passed either through a chest wall trocar or the working incision. This catheter is inserted either under robotic, endoscopic, or direct vision (Fig. 18.5).

Recently, our group switched from blood cardioplegia to Custodiol–Bretschneider’s HTK solution (Franz Köhler Chemie Bensheim GMBH, Germany) as it provides much longer myocardial protection without requiring frequent reinfusions. For maximal myocardial protection, we combine this antegrade cardioplegia with a systemic blood inflow temperature of 28°C. If blood cardioplegia is used, repeat administrations should be delivered at 15- to 30-minute intervals. Multiple cardioplegia infusions, requiring atrial retractor relaxation and repositioning, can entrain air into the aortic root.

For patients having had a previous sternotomy, we cool the patient systemically to 26°C and induce ventricular fibrillation by rapid pacing with a custom Swan–Ganz catheter. In patients with mild aortic insufficiency, additional intracardiac suction can be combined with dropping perfusion flow briefly for difficult suture placement.

After going on CPB, the pericardium is opened longitudinally approximately 3 cm anterior to the phrenic nerve, using either long-shafted endoscopic or robotic instruments. Two to three well-spaced pericardial retraction sutures are placed along the inferior (dorsal) pericardial edge (Fig. 18.6). By passing the needle through the end loop, only one suture is withdrawn through the chest wall using a crochet hook instrument. Care should be taken not to stretch or injure the phrenic nerve. The anterior (ventral) pericardial edge is then suspended with two sutures that are brought through the working incision.

An organized team is paramount for a successful robotic cardiac surgical program. This includes anesthesiologists, surgeons, tableside assistants, scrub personnel, circulating nurses, and perfusionists. Team and procedure training at an experienced robotic valve center has been very important when launching successful programs. Surgeons should be accomplished at mitral and tricuspid repairs before beginning this new trek. Before applying robotic methods, the team should master needed peripheral perfusion techniques as well as operating through minimally invasive incisions. After team comfort has been achieved, progression to robotic mitral valve operations is reasonable and gratifying. It is important to remember that robotic instruments are only access tools and not the operation.